Improved Flux Pinning in Y-Ba-Cu-O Superconductors Containing Niobium Oxide

• Published in: IEEE transactions on applied superconductivity Vol. 19; no. 3; pp. 2970 - 2973
• Main Authors: Yeoh, W.K., Pathak, S.K., Yunhua Shi, Dennis, A.R., Cardwell, D.A., Babu, N.H., Strasik, M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.06.2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Bulk YBCO; Chemicals; Critical current density; CURRENT DENSITY; DENSITY; Doping; Electrical engineering. Electrical power engineering; Electromagnets; Exact sciences and technology; Flux pinning; FLUXES; High temperature superconductors; Magnetic fields; Magnetic materials; melt textured superconductor; MICROSTRUCTURES; Nanomaterials; Nanostructure; Niobium; Niobium oxides; oxide particle doping; OXIDES; PINNING; Superconductivity; SUPERCONDUCTORS; Various equipment and components; YBCO superconductors; Yttrium; Yttrium barium copper oxide; YTTRIUM OXIDE; High strength current; Critical current density; Doping; Doped materials; Irreversible process; High temperature; oxide particle doping; Low field; Solidification; Bulk YBCO; Flux pinning; High current; Sintering; High field; melt textured superconductor; Growth from melt; High temperature superconductor
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2009.2019131

The effect of the addition of niobium oxide (NbO 2 ) on the critical current density of large, single grain bulk YBCO superconductors fabricated by top seeded melt growth (TSMG) has been investigated. The high field critical current density, J c , of NbO 2 doped YBCO is improved significantly even though J c in the low field region is generally lower than in undoped samples. Under these conditions, when field is applied parallel to the c-axis (H//c) , J c is enhanced by more than an order of magnitude at 4 T at 77 K to 2 times 10 3 A/cm 2 for the NbO 2 containing sample. This enhancement in J c is accompanied by a large increase in irreversibility field, H irr , from 4 T for the undoped sample to over 6 T. Enhanced flux pinning at high field is due to the formation of a nano-scale Nb-rich phase during high temperature sintering, melting and solidification of the bulk superconductor.